Printing press



March 7, 1933. 'c PRlTcHAD 1,900,664

\ PRINTING PRESS Filed Oct. 31, 1930 3 Sheets-Sheet l awvemto'e CHRL PR/TCHFIRD 931 25111 61%, M

March 1933, c. G. PRITCHARD PRINTING PRESS Filed Oct.' 51, 1930 3 Sheets-Sheet 2 l l '1 I J.

Suva W601. CHRL PRITGHHRD Patented Mar. 7, 1933 UNITED STATES PATENT "oFFi-cs C ARL GiPRITCI-IARD, OF HIE-AM, OHIO, ASSIGNOR T HARRIS-SEYBOLD-POTT'ER COMP" PANY, OF CLEVELAND, OHIO, A CORPORATION OF DELAWARE rnm'rrne rnnss Application filed October 31, 1930. Serial No. 492,391.

My invention relates to rotary printingpresses particularly of the gravure type eniploying cylinders etched by photo-mechanical processes, and especially to the means for tensioning or clamping the tubular copper plate or shell that is slipped over the platecylinder forming the printing couple with the impression-cylinder.

Heretofore the common practice has been until recently in using rotogravure plate-cylinders to have the cylinder carry a heavy copper shell on its periphery, which shell is successively ground down after each job to receive a fresh design. After the cylinder I5 becomes of too small diameter for thepress,

it must be removed from the press and a new shell built up on the cylinder to the proper original diameter.

According to recent methods a thin coppershell is deposited on a cast-iron core or mandrel by electroplating which shell is then slipped off the core and placed on the plate cylinder of the press, the object being to have this shell used for only one design and then replaced by a similar shell for the next job.

The object of my invention is, among other things, the provision of novel and simplified means for clamping and firmly holding such tubular shells slipped over the plate-cylinder so that such shell will not slip or creep on the cylinder during the printing process.

In asheet-fed press such means are located in the plate-cylinder opposite the usual opening in the impression-cylinder so that '35 no printing pressure is exerted from the impression-cylinder on the shell adjacent such tensioning means when the press is-printing the successive sheets.

. lVith these and other objects in view, the invention comprises certain V constructions hereinafter described and then particularly pointed out in the claims, and a preferred embodiment ofmy invention is illustrated in the accompanying drawings in which Fig. 1 is a side elevation of a printing couple embodying my invention, the platecylinder being partly cut away to show some of the parts in vertical section;

Fig. 2 is an end view of the plate-cylinder partly in section on the line 22 of Fig. 1;

Fig. 3 is a top plan View of the plate-cyl- Fig. 5 is an end view of the tubular shell with a reinforcingstrip attached to theshell. construction of.

to be used in the modified F ig. 4;

Fig. 6 is an' enlarged section on the line 6- -6 of Fig. 5; and

Fig. 7 is a top planfv iew of the plate 7 cylinder shown in Fig. 4:.

Similar numerals refer to similar parts throughout the several figures.

Referring to Figs. 1, 2 and 3, the impression-cylinder 8 coacts with the plate-cylinder 9 to form a printing couple, the cyIinderS having the cut-out portion 10' within which are arranged the cylinder grippers 11 to carry the sheet 12 into the bite of the cylinders 8 and 9 in the usual way. The platecylinder 9 is longitudinally slotted or grooved at 13 opposite the cut-out portion lOto receive the collapsiblesegment 14 which is used to tension the tubular copper shell 15 slippedover the plate-cylinder 9. V

The segment 14 comprises the base plate 16 carrying a plurality of upright'pins 17' at each end of the plate 16, the pins 17 acting to position a like number of heavy coilsprings 18 seatedin corresponding recesses. formed in the upper block l9'extending longitudinally through the slot.13 in the cylin der 9. The block 19 has the outwardly projecting lugs 20 formed along its inner lower edges so shaped to engage the inner abutinents 21 of the cylinder 9 when thecurved top 22 of the block 19 is flush with the circumference of the cylinder 9' as shown in Fig; 1.

Means are provided for compressing and locking the segment l l'below the chord of the arc of the cy1inder 9 so that the shell.

15 may he slipped over the end of the cyl inder 9 and be positioned thereon: In the embodiment shown, the end members'23 arranged at the ends of the block 19 have suitable holes 24 bored therein to be engaged by pins 25 passing through holes 26in the levers 27 removably pivoted to the cylinder 9 by the screw-studs 28. The end of each lever 27 is connected by the detachable link 29 to the locking rock-arm 30 pinned to the cylinder 9 by the stud 31. The rock-arm 30 carries the lug 32 recessed at 33 to be engaged by the removable locking-bar 3 1 to throw the rock arm 30 over center at 31. as indicated by.

dotted lines in Fig. 1.

When the block 19 is so depressed or 001- lapsed with coil springs 18 compressed, the shell 15 is positioned on the plate cylinder 9, and thereafter the block 19 is released to rise radially in the groove 13 to normal position (Fig. 1), to tighten or tension the shell 15 to make a true cylinder, the shell 15 being made very slightly smaller in diameter so as to be put under tension by the springpressed block 19. The outer peripheral surface of the top 22 of the block 19. may be slightly roughened, if desired,'in order to bite into the inner surface of the shell 15 and so prevent the latter from shifting its position on the cylinder 9. The block 19 is not subjected to printing pressure because of the oppositely-disposed cut-out portion 10 in the cylinder 8, and so the uniform pressure exerted by the springs 18 is not disturbed in the printing operation. Fig. 3 shows how the compressing and locking means for the segment 14; at either end of the cylinder 9 V (Fig. 2) may be released so that such segment may be shifted and positioned within the grooved slot 13 before the shell 15 is slipped over the cylinder 9.

- Referring to the modified form of Figs. 47, the depressible block 19 has its top 22 formed with a longitudinal groove 35 to refceive the longitudinal reinforcing strip 36 affixed to the inner surface'of the shell 15 as shown in Figs. 5 and 6. The mechanism for compressing and locking the block '19 is the same as that already described herein in the Figs. 13 construction.

My preferred method of, attaching the reinforcing strip 36 to the shell 15 is by placing the strip 36 in a groove cut in the core or mandre used in electroplating the tubular shell on such core as before described, so that such strip is-firmly afliXed during such electroplating' to the inner peripheralsurface of such shell during its formation.

The] groove 35 and strip 36 are shown in coacting engagement in 7 and serve as a positive registering device for the shell 15 on the cylinder 9 and also preclude any possi ble creeping of the shell on the cylinder during the printing since the strip 36 fits snugly in the groove 35. 7

Changes and variations may be made in the constructions shown and described without departing from the principles of the invention or sacrificing its chief advantages;

hence such invention is not to be confined to the structures shown in the accompanying drawings.

I claim as my invention 1. In combination, a printing cylinder, a tubular plate fitted over said cylinder and spring-pressed, radially movable means within the cylinder to tension the plate thereon.

2. In combination, a printing cylinder having a gap, a tubular plate fitted over said cylinder and spring-pressed, radially movable means within the cylinder gap to tension the plate thereon.

3. In combination, a'printing cylinder, a tubular plate fitted over said cylnder, springpressed, radially expansible means within the cylinder normally tensioning the plate thereon, and 11163.11S't0 move said means inwardly within the cylinder while compressing said spring to permit positioning of the tubular plate on the cylinder.

4. In combination, a printing cylinder, a tubular plate fitted over said cylinder, spring-pressed, radially expansible means within the cylinder normally tensioning the plate thereon, and means to move and lock said means inwardly within the cylinder while compressing said spring to permit positioning of the tubular plate on the cylinder.

5. In combination, a printing cylinder, a tubular plate fitted over said cylinder, spring-pressed, radially expansible means within the cylinder normally tensioning the plate thereon, and detachable means to move and lock said means inwardly within the cylinder while compressing said spring to permit positioning of the tubular plate on the cylinder.

I 6. In combination, a printing cylinde having a gap, a cylindrical plate shell fitted peripherally on said cylinder, expansible means within the cylinder gap normally tensioning and holding the plate shell in position, and means to compress said spring and move said expansible means within the cylinder gap to permit positioning of the plate shell on the cylinder.

7. In a rotary printing-press, an impression cylinder and a printing cylinder both cylinders having coincident gaps to comprise a printing couple, a tubular plate fitted over the printing cylinder, and spring-pressed, radially eXpansible means within the printing cylinder gap opposite the impression cylinder gap to tension the plate on its cylinder out of contact with the impression cylinder.

8. In a rotary printing-press, an impression cylinder and a printing cylinder both cylinders having coincident gaps to comprise a printing couple, a tubular plate fitted over the printing cylinder, and spring-pressed, radially expansible means within the prints ing cylinder gap opposite the impression cylinder gap to tension the plate on its cylinder out of contact with the impression cylinder.

9. In combination, a printing cylinder, a tubular plate fitted over said cylinder, means longitudinally projecting along the inner surface of said plate and engaging said cylinder to hold the plate in fixed relation with said cylinder, and means bearing on said strip to tension the plate on the cylinder.

10. In combination, a printing cylinder, a tubular plate fitted over said cylinder, means longitudinally projecting along the inner surface of said plate and engaging a longitudinal groove on the periphery of said cylinder to hold the plate in fixed relation with said cylinder, and means bearing on said strip to tension the plate on the cylinder.

11. In combination, a printing cylinder having a gap, a tubular plate having a longitudinal strip on its inner surface fitted over said cylinder, and radially movable means having its outer surface grooved to contain said strip carried within the cylinder gap to tension the plate on the cylinder.

12. In combination, a printing cylinder having a gap, a tubular plate having a l0ngitudinal strip on its inner surface fitted over said cylinder, and spring-pressed, radially movable means having its outer surface grooved to contain said strip carried Within the cylinder gap to tension the plate on the cylinder.

13. In combination, a printing cylinder, a tubular plate fitted over said cylinder, spring-pressed, radially expansible means within the cylinder to tension the plate thereon, and means to limit the outward radial movement of said means bearing on said plate. 7

CARL G. PRITCHABD. 

